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Biomedical subjects

F C Delori

Publications and source records attributed to F C Delori.

44 records · Page 3Linked to original sources
PubMed1979

Image formation in fundus cameras.

Imaging in a fundus camera depends more on design of the system than on correction of the first fundus image as formed by the ophthalmoscopic lens. We show here that the designer may use the free parameters of the ophthalmoscopic lens (contact or noncontact) to correct the latter for observation and illumination of the fundus. In both contact and noncontact systems the fundus is illuminated by forming a ring of light on the patient's cornea around a central area (the corneal window) reserved for observation. On the first surface of the crystalline lens, the light also forms a ring which must accomodate the total entrance pupil (TEP) of the observation system in its middle and which is limited on the outside by the patient's iris. The restrictions that result from this situation define the entrance pupil of the bundle of rays that image the marginal point of the retina. The limits of this bundle are imposed by the choice of the angular field of view and by the size of the patient's pupil.

Fundus Oculi↗
PubMed1977

Monochromatic ophthalmoscopy and fundus photography. The normal fundus.

Anatomical details in the ocular fundus can be seen with increased contrast when appropriate monochromatic illumination is used. This technique permits more accurate visualization and documentation than can be achieved with white light. This article reports the optimal spectral ranges for visualization of the different fundus structures. It describes and illustrates the appearance of individual structures and areas of the fundus under different spectral illuminations. There is a detailed discussion of the optical properties of the fundus layers that provides a background for interpreting the data and a baseline for examination of pathologic conditions.

Adolescent↗
PubMed1977

Clinical trials with the Equator-Plus camera.

The Equator-Plus camera can photograph a 148-degree view of the fundus, measured from the nodal point of the eye. We tested this instrument clinically more than 800 times on over 700 eyes. The large field, which is three to four times that of any conventional fundus camera, is achieved by using a special contact lens as the front element in the camera optics. Photographs taken with the Equator-Plus camera can resolve a lesion as small as one-eighth of a disk diameter, if the contrast is good. Protruding tumors, choroidal or retinal detachment, and extensive disease of the choroid and fundus show up well with this technique. We obtained good pictures in 87% of the clinical tests. We have not observed complications of any kind after photography with the Equator-Plus camera.

Adolescent↗
PubMed1976

Examination of the ocular fundus with monochromatic light.

Pure colored light in a narrow spectral band improves ophthalmoscopy and photography of the human ocular fundus. The contrast of fundus details is enhanced and the loss of quality of the image associated with chromatic aberrations is eliminated. The monochromatic technique also improves the localization of structures in the stratified layers of the fundus. Monochromatic photographs of a normal fundus and different pathologic cases are presented and discussed.

Eye Diseases↗
PubMed1975

Excitation and emission spectra of fluorescein dye in the human ocular fundus.

The excitation and emission spectra of fluorescein dye were determined during angiography from different sites in the human ocular fundus. All spectra were markedly shifted toward longer wavelengths relative to the spectra of fluorescein in aqueous solution. This effect is most pronounced for the macular area; however, it decreases for the choroidal background and even more for the retinal vessels. The results are relevant to the selection of optical filter combinations for fluorescein angiography.

Adolescent↗